Using Alias Child Logger in Actions

You can use the Alias function to include a user-defined alias in the logs for Mutate, Validate, and Watch actions. This can make for easier debugging since your user-defined alias will be included in the action’s logs. This is especially useful when you have multiple actions of the same type in a single module.

The below example uses Mutate, Validate, and Watch actions with the Alias function:

When(a.Pod)
  .IsCreatedOrUpdated()
  .Alias("mutate")
  .Mutate((po, logger) => {
    logger.info(`alias: mutate ${po.Raw.metadata.name}`);
  });
When(a.Pod)
  .IsCreatedOrUpdated()
  .Alias("validate")
  .Validate((po, logger) => {
    logger.info(`alias: validate ${po.Raw.metadata.name}`);
    return po.Approve();
  });
When(a.Pod)
  .IsCreatedOrUpdated()
  .Alias("watch")
  .Watch((po, _, logger) => {
    logger.info(`alias: watch ${po.metadata.name}`);
  });
When(a.Pod)
  .IsCreatedOrUpdated()
  .Alias("reconcile")
  .Reconcile((po, _, logger) => {
    logger.info(`alias: reconcile ${po.metadata.name}`);
  });

This will result in log entries when creating a Pod with the that include the alias:

Logs for Mutate When Pod red is Created:

{"level":30,"time":1726632368808,"pid":16,"hostname":"pepr-static-test-6786948977-6hbnt","uid":"b2221631-e87c-41a2-94c8-cdaef15e7b5f","namespace":"pepr-demo","name":"/red","gvk":{"group":"","version":"v1","kind":"Pod"},"operation":"CREATE","admissionKind":"Mutate","msg":"Incoming request"}
{"level":30,"time":1726632368808,"pid":16,"hostname":"pepr-static-test-6786948977-6hbnt","uid":"b2221631-e87c-41a2-94c8-cdaef15e7b5f","namespace":"pepr-demo","name":"/red","msg":"Processing request"}
{"level":30,"time":1726632368808,"pid":16,"hostname":"pepr-static-test-6786948977-6hbnt","msg":"Executing mutation action with alias: mutate"}
{"level":30,"time":1726632368808,"pid":16,"hostname":"pepr-static-test-6786948977-6hbnt","alias":"mutate","msg":"alias: mutate red"}
{"level":30,"time":1726632368808,"pid":16,"hostname":"pepr-static-test-6786948977-6hbnt","uid":"b2221631-e87c-41a2-94c8-cdaef15e7b5f","namespace":"pepr-demo","name":"hello-pepr","msg":"Mutation action succeeded (mutateCallback)"}
{"level":30,"time":1726632368808,"pid":16,"hostname":"pepr-static-test-6786948977-6hbnt","uid":"b2221631-e87c-41a2-94c8-cdaef15e7b5f","namespace":"pepr-demo","name":"/red","res":{"uid":"b2221631-e87c-41a2-94c8-cdaef15e7b5f","allowed":true,"patchType":"JSONPatch","patch":"W3sib3AiOiJhZGQiLCJwYXRoIjoiL21ldGFkYXRhL2Fubm90YXRpb25zL3N0YXRpYy10ZXN0LnBlcHIuZGV2fjFoZWxsby1wZXByIiwidmFsdWUiOiJzdWNjZWVkZWQifV0="},"msg":"Check response"}
{"level":30,"time":1726632368809,"pid":16,"hostname":"pepr-static-test-6786948977-6hbnt","uid":"b2221631-e87c-41a2-94c8-cdaef15e7b5f","method":"POST","url":"/mutate/c1a7fb6e3f2ab9dc08909d2de4166987520f317d53b759ab882dfd0b1c198479?timeout=10s","status":200,"duration":"1 ms"}

Logs for Validate When Pod red is Created:

{"level":30,"time":1726631437605,"pid":16,"hostname":"pepr-static-test-6786948977-j7f9h","uid":"731eff93-d457-4ffc-a98c-0bcbe4c1727a","namespace":"pepr-demo","name":"/red","gvk":{"group":"","version":"v1","kind":"Pod"},"operation":"CREATE","admissionKind":"Validate","msg":"Incoming request"}
{"level":30,"time":1726631437606,"pid":16,"hostname":"pepr-static-test-6786948977-j7f9h","uid":"731eff93-d457-4ffc-a98c-0bcbe4c1727a","namespace":"pepr-demo","name":"/red","msg":"Processing validation request"}
{"level":30,"time":1726631437606,"pid":16,"hostname":"pepr-static-test-6786948977-j7f9h","uid":"731eff93-d457-4ffc-a98c-0bcbe4c1727a","namespace":"pepr-demo","name":"hello-pepr","msg":"Processing validation action (validateCallback)"}
{"level":30,"time":1726631437606,"pid":16,"hostname":"pepr-static-test-6786948977-j7f9h","msg":"Executing validate action with alias: validate"}
{"level":30,"time":1726631437606,"pid":16,"hostname":"pepr-static-test-6786948977-j7f9h","alias":"validate","msg":"alias: validate red"}
{"level":30,"time":1726631437606,"pid":16,"hostname":"pepr-static-test-6786948977-j7f9h","uid":"731eff93-d457-4ffc-a98c-0bcbe4c1727a","namespace":"pepr-demo","name":"hello-pepr","msg":"Validation action complete (validateCallback): allowed"}
{"level":30,"time":1726631437606,"pid":16,"hostname":"pepr-static-test-6786948977-j7f9h","uid":"731eff93-d457-4ffc-a98c-0bcbe4c1727a","namespace":"pepr-demo","name":"/red","res":{"uid":"731eff93-d457-4ffc-a98c-0bcbe4c1727a","allowed":true},"msg":"Check response"}
{"level":30,"time":1726631437606,"pid":16,"hostname":"pepr-static-test-6786948977-j7f9h","uid":"731eff93-d457-4ffc-a98c-0bcbe4c1727a","method":"POST","url":"/validate/c1a7fb6e3f2ab9dc08909d2de4166987520f317d53b759ab882dfd0b1c198479?timeout=10s","status":200,"duration":"5 ms"}

Logs for Watch and Reconcile When Pod red is Created:

{"level":30,"time":1726798504518,"pid":16,"hostname":"pepr-static-test-watcher-6dc69654c9-5ql6b","msg":"Executing reconcile action with alias: reconcile"}
{"level":30,"time":1726798504518,"pid":16,"hostname":"pepr-static-test-watcher-6dc69654c9-5ql6b","alias":"reconcile","msg":"alias: reconcile red"}
{"level":30,"time":1726798504518,"pid":16,"hostname":"pepr-static-test-watcher-6dc69654c9-5ql6b","msg":"Executing watch action with alias: watch"}
{"level":30,"time":1726798504518,"pid":16,"hostname":"pepr-static-test-watcher-6dc69654c9-5ql6b","alias":"watch","msg":"alias: watch red"}
{"level":30,"time":1726798504521,"pid":16,"hostname":"pepr-static-test-watcher-6dc69654c9-5ql6b","msg":"Executing reconcile action with alias: reconcile"}
{"level":30,"time":1726798504521,"pid":16,"hostname":"pepr-static-test-watcher-6dc69654c9-5ql6b","alias":"reconcile","msg":"alias: reconcile red"}
{"level":30,"time":1726798504521,"pid":16,"hostname":"pepr-static-test-watcher-6dc69654c9-5ql6b","msg":"Executing watch action with alias: watch"}
{"level":30,"time":1726798504521,"pid":16,"hostname":"pepr-static-test-watcher-6dc69654c9-5ql6b","alias":"watch","msg":"alias: watch red"}
{"level":30,"time":1726798504528,"pid":16,"hostname":"pepr-static-test-watcher-6dc69654c9-5ql6b","msg":"Executing reconcile action with alias: reconcile"}
{"level":30,"time":1726798504528,"pid":16,"hostname":"pepr-static-test-watcher-6dc69654c9-5ql6b","alias":"reconcile","msg":"alias: reconcile red"}
{"level":30,"time":1726798504528,"pid":16,"hostname":"pepr-static-test-watcher-6dc69654c9-5ql6b","msg":"Executing watch action with alias: watch"}
{"level":30,"time":1726798504528,"pid":16,"hostname":"pepr-static-test-watcher-6dc69654c9-5ql6b","alias":"watch","msg":"alias: watch red"}
{"level":30,"time":1726798510464,"pid":16,"hostname":"pepr-static-test-watcher-6dc69654c9-5ql6b","msg":"Executing watch action with alias: watch"}
{"level":30,"time":1726798510464,"pid":16,"hostname":"pepr-static-test-watcher-6dc69654c9-5ql6b","alias":"watch","msg":"alias: watch red"}
{"level":30,"time":1726798510466,"pid":16,"hostname":"pepr-static-test-watcher-6dc69654c9-5ql6b","msg":"Executing reconcile action with alias: reconcile"}
{"level":30,"time":1726798510466,"pid":16,"hostname":"pepr-static-test-watcher-6dc69654c9-5ql6b","alias":"reconcile","msg":"alias: reconcile red"}

Note: The Alias function is optional and can be used to provide additional context in the logs. You must pass the logger object as shown above to the action to use the Alias function.

See Also

Looking for some more generic helpers? Check out the Module Author SDK for information on other things that Pepr can help with.